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Finding the Fourth Proportional to 718.40, 990.20 and 560.72

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Solution

The fourth proportional to 718.40, 990.20 and 560.72 is: 772.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.40 : 990.20 = 560.72 : x
  2. Step 2: Convert to fraction form
    718.40/990.20 = 560.72/x
  3. Step 3: Cross multiply
    718.40x = 990.20 × 560.72
  4. Step 4: Simplify right side
    718.40x = 555,217.19
  5. Step 5: Solve for x
    x = 555,217.19/718.40
  6. Step 6: Final answer
    x = 772.86

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.